Thanks again John. The only plugins activated are ACF Pro and the ACF repeater field. I haven’t added any other pre_save_post anywhere else (not in my header, page, footer or functions.php) and I only have one acf_form_head() which is at the top of my single-post.php file, just before get_header().
I guess if no one else is having this problem it must just be something to do with my set up?
Thanks again for all your help…
